646999562234897 has 2 divisors, whose sum is σ = 646999562234898. Its totient is φ = 646999562234896.

The previous prime is 646999562234813. The next prime is 646999562234923. The reversal of 646999562234897 is 798432265999646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 333091846646416 + 313907715588481 = 18250804^2 + 17717441^2 .

It is a cyclic number.

It is not a de Polignac number, because 646999562234897 - 2⁴⁰ = 645900050607121 is a prime.

It is a super-4 number, since 4×646999562234897⁴ (a number of 60 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is not a weakly prime, because it can be changed into another prime (646999562230897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323499781117448 + 323499781117449.

It is an arithmetic number, because the mean of its divisors is an integer number (323499781117449).

Almost surely, 2^{646999562234897} is an apocalyptic number.

It is an amenable number.

646999562234897 is a deficient number, since it is larger than the sum of its proper divisors (1).

646999562234897 is an equidigital number, since it uses as much as digits as its factorization.

646999562234897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76187381760, while the sum is 89.

The spelling of 646999562234897 in words is "six hundred forty-six trillion, nine hundred ninety-nine billion, five hundred sixty-two million, two hundred thirty-four thousand, eight hundred ninety-seven".